Java tutorial
/* * jabsorb - a Java to JavaScript Advanced Object Request Broker * http://www.jabsorb.org * * Copyright 2007-2008 The jabsorb team * * based on original code from * JSON-RPC-Java - a JSON-RPC to Java Bridge with dynamic invocation * * Copyright Metaparadigm Pte. Ltd. 2004. * Michael Clark <michael@metaparadigm.com> * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * */ package org.jabsorb.ng.serializer.impl; import java.util.Dictionary; import java.util.Enumeration; import java.util.Hashtable; import java.util.Iterator; import java.util.Properties; import org.jabsorb.ng.JSONSerializer; import org.jabsorb.ng.serializer.AbstractSerializer; import org.jabsorb.ng.serializer.MarshallException; import org.jabsorb.ng.serializer.ObjectMatch; import org.jabsorb.ng.serializer.SerializerState; import org.jabsorb.ng.serializer.UnmarshallException; import org.json.JSONException; import org.json.JSONObject; /** * Serializes Dictionaries and Properties */ public class DictionarySerializer extends AbstractSerializer { /** * Classes that this can serialize to. */ private static Class<?>[] _JSONClasses = new Class<?>[] { JSONObject.class }; /** * Classes that this can serialize. */ private static Class<?>[] _serializableClasses = new Class<?>[] { Properties.class, Dictionary.class, Hashtable.class }; /** * Unique serialization id. */ private static final long serialVersionUID = 2; @Override public boolean canSerialize(final Class<?> clazz, final Class<?> jsonClazz) { return (super.canSerialize(clazz, jsonClazz) || ((jsonClazz == null || jsonClazz == JSONObject.class) && Dictionary.class.isAssignableFrom(clazz))); } @Override public Class<?>[] getJSONClasses() { return _JSONClasses; } @Override public Class<?>[] getSerializableClasses() { return _serializableClasses; } @Override public Object marshall(final SerializerState state, final Object p, final Object o) throws MarshallException { final Dictionary<?, ?> dictionary = (Dictionary<?, ?>) o; final JSONObject obj = new JSONObject(); final JSONObject mapdata = new JSONObject(); try { if (ser.getMarshallClassHints()) { obj.put("javaClass", o.getClass().getName()); } obj.put("map", mapdata); state.push(o, mapdata, "map"); } catch (final JSONException e) { throw new MarshallException("Could not put data" + e.getMessage(), e); } Object key = null; try { final Enumeration<?> en = dictionary.keys(); while (en.hasMoreElements()) { key = en.nextElement(); final String keyString = key.toString(); // only support String // keys final Object json = ser.marshall(state, mapdata, dictionary.get(key), keyString); // omit the object entirely if it's a circular reference or // duplicate // it will be regenerated in the fixups phase if (JSONSerializer.CIRC_REF_OR_DUPLICATE != json) { mapdata.put(keyString, json); } } } catch (final MarshallException e) { throw new MarshallException("map key " + key + " " + e.getMessage(), e); } catch (final JSONException e) { throw new MarshallException("map key " + key + " " + e.getMessage(), e); } finally { state.pop(); } return obj; } // TODO: try unMarshall and unMarshall share 90% code. Put in into an // intermediate function. // TODO: Also cache the result somehow so that an unmarshall // following a tryUnmarshall doesn't do the same work twice! @Override public ObjectMatch tryUnmarshall(final SerializerState state, final Class<?> clazz, final Object o) throws UnmarshallException { final JSONObject jso = (JSONObject) o; String java_class; // Hint presence try { java_class = jso.getString("javaClass"); } catch (final JSONException e) { throw new UnmarshallException("Could not read javaClass", e); } if (java_class == null) { throw new UnmarshallException("no type hint"); } // Class compatibility check if (!classNameCheck(java_class)) { throw new UnmarshallException("not a Dictionary"); } // JSON Format check JSONObject jsonmap; try { jsonmap = jso.getJSONObject("map"); } catch (final JSONException e) { throw new UnmarshallException("map missing", e); } if (jsonmap == null) { throw new UnmarshallException("map missing"); } // Content check final ObjectMatch m = new ObjectMatch(-1); state.setSerialized(o, m); final Iterator<?> i = jsonmap.keys(); String key = null; try { while (i.hasNext()) { key = (String) i.next(); m.setMismatch(ser.tryUnmarshall(state, null, jsonmap.get(key)).max(m).getMismatch()); } } catch (final UnmarshallException e) { throw new UnmarshallException("key " + key + " " + e.getMessage(), e); } catch (final JSONException e) { throw new UnmarshallException("key " + key + " " + e.getMessage(), e); } return m; } @Override public Object unmarshall(final SerializerState state, final Class<?> clazz, final Object o) throws UnmarshallException { final JSONObject jso = (JSONObject) o; String java_class; // Hint check try { java_class = jso.getString("javaClass"); } catch (final JSONException e) { throw new UnmarshallException("Could not read javaClass", e); } if (java_class == null) { throw new UnmarshallException("no type hint"); } // Create the dictionary Hashtable<Object, Object> dictionary; if (java_class.equals("java.util.Dictionary") || java_class.equals("java.util.Hashtable")) { dictionary = new Hashtable<Object, Object>(); } else if (java_class.equals("java.util.Properties")) { dictionary = new Properties(); } else { throw new UnmarshallException("not a Dictionary"); } // Parse the JSON map JSONObject jsonmap; try { jsonmap = jso.getJSONObject("map"); } catch (final JSONException e) { throw new UnmarshallException("map missing", e); } if (jsonmap == null) { throw new UnmarshallException("map missing"); } state.setSerialized(o, dictionary); final Iterator<?> i = jsonmap.keys(); String key = null; try { while (i.hasNext()) { key = (String) i.next(); dictionary.put(key, ser.unmarshall(state, null, jsonmap.get(key))); } } catch (final UnmarshallException e) { throw new UnmarshallException("key " + key + " " + e.getMessage(), e); } catch (final JSONException e) { throw new UnmarshallException("key " + key + " " + e.getMessage(), e); } return dictionary; } }